What's more relevant in this film it's the remarkable process by which the flashbacks are introduced, a theatrical process of statement exponentiation and its enunciation. A bridge in the past is a break in the narration through a discourse of light - a cut in the present. Later, Nagisa Oshima with "Night and Fog in Japan", would do a masterpiece based on a similar process.
I want to know how they did those flashbacks - what a technique! The actor is in the foreground while the background fades away and then the cut is delivered on action - making a seamless transition. All this before CGI.